Graphing

VectorMation provides two ways to plot mathematical functions: Graph (full axes, ticks, labels) and FunctionGraph (bare curve only).

Graph

Basic Usage

Example: Basic sin graph

"""Basic sin graph on axes."""
import math
from vectormation.objects import *

v = VectorMathAnim()
v.set_background()

graph = Graph(math.sin, x_range=(-2 * math.pi, 2 * math.pi),
              y_range=(-1.5, 1.5))

v.add(graph)

v.show(end=0)

Constructor

Graph(func, x_range=(-5, 5), y_range=None, num_points=200,
      x=100, y=50, plot_width=800, plot_height=600,
      x_label='x', y_label='y', show_grid=False,
      creation=0, z=0, **styling_kwargs)

Parameter	Description
func	A callable f(x) -> y
x_range	(x_min, x_max) in math coordinates
y_range	(y_min, y_max) or None for auto
num_points	Number of sample points for the curve
x, y	Top-left position of the plot area in SVG pixels
plot_width, plot_height	Size of the plot area in SVG pixels
x_label, y_label	Axis labels (set to '' to hide)
show_grid	Show grid lines at tick positions
**styling_kwargs	Passed to the curve (e.g. stroke, stroke_width)

The default curve colour is #58C4DD (light blue) with stroke_width=3.

Auto Y-Range

If y_range is not specified, the graph samples the function across the x-range and automatically determines appropriate y-axis bounds with 5% padding.

Adding More Functions

cos_curve = graph.add_function(math.cos, stroke='#FC6255')

add_function() returns a Path object, which you can animate independently:

cos_curve.create(start=2, end=4)

Animating the Curve

The graph’s curve is a Path accessible as graph.curve. You can animate it:

graph.curve.create(start=0, end=2)      # animate drawing
graph.curve.fadein(start=0, end=1)      # fade in

Sub-Objects

Attribute	Type	Description
graph.curve	Path	The main function curve
graph.x_min / x_max	Real	Animated x-axis range bounds
graph.y_min / y_max	Real	Animated y-axis range bounds

Coordinate Mapping

The graph provides methods for mapping between math and SVG coordinates:

• Math x/y values are mapped linearly to the SVG plot area

• The y-axis is inverted (SVG y increases downward)

• The axes are positioned at the math origin (0, 0) when it falls within the range

• coords_to_point(x, y, time=0) converts math coordinates to SVG pixels

Animated Ranges

The axis ranges (x_min, x_max, y_min, y_max) are Real attributes, so they can be animated like any other property. Use the convenience methods to animate both ends at once:

ax.set_x_range(0, 2, (1, 4))           # animate x-axis bounds
ax.set_y_range(0, 2, (0, 18))          # animate y-axis bounds
ax.set_ranges((1, 4), (0, 18), start=0, end=2)   # animate both at once

You can also animate individual bounds directly:

ax.x_max.move_to(0, 2, 20)  # only change the upper x bound

Example: Animated axis zoom

Axis decorations (lines, ticks, tick labels, grid) automatically re-render each frame to match the current range. Curves resample the function at each frame too, so everything stays in sync.

"""Axes zoom with animated ranges."""
from vectormation.objects import *

v = VectorMathAnim()
v.set_background()

ax = Axes(x_range=(-5, 5), y_range=(-2, 26))
curve = ax.plot(lambda x: x ** 2, stroke='#58C4DD')

# Zoom into x=[1, 4], y=[0, 18]
ax.set_ranges((1, 4), (0, 18), start=0, end=2)

v.add(ax)

v.show(end=3)

Example: Animated Graph

Example: Animated sin + cos

Draw a sin curve, then add and animate a cos curve on the same axes.

"""Animated sin + cos graph creation."""
import math
from vectormation.objects import *

v = VectorMathAnim()
v.set_background()

graph = Graph(math.sin, x_range=(-2 * math.pi, 2 * math.pi),
              y_range=(-1.5, 1.5))

# Draw sin curve
graph.curve.create(start=0, end=2)

# Add and draw cos curve
cos_curve = graph.add_function(math.cos, stroke='#FC6255')
cos_curve.create(start=2.5, end=4.5)

v.add(graph)

v.show(end=5)

---

FunctionGraph

FunctionGraph plots a function as a bare polyline – no axes, ticks, or labels. Useful when you only need the curve itself, or want to compose it with other objects.

Constructor

FunctionGraph(func, x_range=(-5, 5), y_range=None, num_points=200,
              x=100, y=50, width=800, height=600,
              creation=0, z=0, **styling_kwargs)

Parameter	Description
func	A callable f(x) -> y
x_range	(x_min, x_max) in math coordinates
y_range	(y_min, y_max) or None for auto
num_points	Number of sample points
x, y	Top-left position of the plot area in SVG pixels
width, height	Size of the plot area in SVG pixels
**styling_kwargs	Passed to the polyline (e.g. stroke, stroke_width)

The default curve style is stroke='#58C4DD', stroke_width=3, fill_opacity=0.

Example

Example: FunctionGraph with draw_along

FunctionGraph extends Lines, so all VObject animation methods (fadein, write, shift, etc.) work directly on it.

"""FunctionGraph with draw_along animation."""
import math
from vectormation.objects import *

v = VectorMathAnim()
v.set_background()

curve = FunctionGraph(math.sin, x_range=(0, 2 * math.pi),
                      width=600, height=300, x=200, y=350)
curve.draw_along(start=0, end=2)

v.add(curve)

v.show(end=3)